This invention relates to emergency parachute packs to be used by crew members of an airplane when bailing out or when the plane is being ditched.
Safety is of paramount importance in both civil and military aviation. One way in which safety can be improved is by the provision of emergency equipment adequate to meet any reasonably predictable emergency. In appropriate circumstances, this includes the provision of parachutes for individual crew members. Additionally, when a possibility of bailing out over water or ditching the plane into a body of water exists, crew members and passengers should have some sort of flotation device such as life rafts, life vests, or floating seat cushions.
Whatever emergency equipment or clothing is provided should not unduly hamper the normal activities of the crew. The wearing of certain parachutes and similar equipment while operating an aircraft has been found to lead to impaired movement fatigue, discomfort, and a resulting disinclination to use the equipment. All of these can detract from the safety of the operation of an aircraft.
Safety equipment should, preferably, be light in weight. Not only does a heavy safety unit compound the disadvantages discussed above, it also adds to the overall weight of the aircraft, contributing to increased fuel consumption and decreased speed.
In the past and currently, the crew members in some military aircraft have worn a back-mounted parachute system which is intended for constant in-flight wearing. While these parachute systems provided reliable operation, and while they completely eliminated the time required to put them on in an emergency, these parachute systems suffered from the disadvantages of being uncomfortable and significantly restricting the movements of the crew member wearing the parachute system. If the crew member removed the parachute system and its associated harness, then the time required to put the parachute system back on in an emergency could be considerable. This could lead to loss of life.
Other military emergency parachute systems designed for aircrew members of some cargo aircraft had chest-mounted parachutes which were detachably connected to adjustable harnesses. These systems were very heavy. In addition, many World War Two vintage aircraft used seat-pack parachutes which were very heavy and uncomfortable.
Civilian emergency parachute systems exist which are lighter, thinner, and more comfortable than the military emergency parachute systems described above. One of the most popular is the Security Safety-Chute, which is a back-mounted chair-type parachute system that forms a complete chair when the crew member sits in the aircraft seat. Civilian emergency parachute systems which have back packs but are not chair-types include the Strong Enterprises ParaCushion Back, the Softie back pack systems, and my own Beta Emergency Back Pack. Further information on emergency parachute systems known to the art can be found in my paper (No. AIAA-81-0413), delivered to the AIAA 19th Aerospace Sciences Meeting in St. Louis, Missouri held on Jan. 12-15, 1981, and published by AIAA. This paper is hereby incorporated by reference in the present specification, as if fully set forth herein.
Emergency flotation devices have been provided for parachutists. Examples of such flotation devices are inflatable life vests and floats which may be attached to the parachutist's clothing or parachute harness, or have harnesses of their own. One such flotation device is the L.P.U. Flotation Chamber, an inflatable U-shaped float which is stored in a packet that may be removeably installed on the reserve parachute or on the harness of a parachutist. The L.P.U. Flotation Chamber does not, however, provide an integrated combination of parachute and flotation device.
The integrated combination of a flotation device with a backpack parachute is known in the prior art, although none of the prior art parachute systems described above have flotation devices. A typical example of a backpack parachute combined with a flotation device is the Navy NB-7 parachute combined with a rigid seat survival kit (RSSK) containing a raft and other equipment, as used by crew members of the E-2C aircraft. Such a combination would be useful when the aircraft is to be flying over water. The resulting combination of parachute and RSSK was a package that extended to the knees of the crew member wearing it. Such a pack was found to be seriously uncomfortable in the E-2C and made emergency egress nearly impossible. Subsequent efforts have been directed at decreasing the length of this assembly. Grumman Aircraft recently developed a system for the Navy that reduced the length and weight of the parachute/flotation assembly used in the E-2C.
The above-mentioned combination prior art device (NB7/RSSK) also suffered from the disadvantage of being relatively heavy, typically 50 pounds or more, as well as uncomfortable. Even the new Grumman assembly weighs approximately 37 lbs.